Means for starting dynamo-electric machines.



W. D. POMEROY. MEANS r011 STARTING mmmo ELECTRIC momma.

APPLIOATIOK rum) MAY 11. 190a.

Patented Jan 12, 1909.

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UNITED STATES PATENT OFFICE.

WILLIAM D. POMEROY, O1 NORWOOD, OHIO, ASSIGNOR TO ALLIS-(.HALMERS COMPANY, A CORPORATION OF NEW JERSEY, AND THE BULLOCK ELEOPRIC MANUFACTURING COM PANY, A CORPORATION OF OHIO.

I MEANS FOR STARTING DYNAMIC-ELECTRIC MACHINES.

Specification of Letters Patent.

Patented Jan. 12, 1909 Application filed May 17, 1950. Serial No. 1111,2112.

To all whom it may concern:

Be'it known that I, WILLIAM D. Poms nor, a citizen of the United States, residin r at Norwood, in the county of Hamilton an 6 State of Ohio, have invented certain new and useful Improvements in Means for Startin Dynamo Electric Machines, of which t e following is a full, clear, and exact specification.

M invention relates to dynamo-electric mac ines and particularl to those which are not self starting, sucr as synchronous motors and other machines which run as synchronous motors includin rotary converters, frequency-changers an other motornerator sets. Such machines above reerred to are usually started and brought up to synchronism by an auxiliary motor, general y an induction motor, mounted on the main shaft. If the main machine to be started is heavy, it very large starting motor is necessary not onl on account of the inertia of the rotor o the main machine, but principall for the reason that the lubricant by t e great weight of the rotor, is squeezed from beneath the shaft while at rest, leaving the shaft resting on the dry bealrings resulting in a high coeflicient of friction. A much larger auxiliary motor is necessary therefore to initially start the rotor of thebmain mhachinehthan would be necessary'to rin t e mac ine u to's nchronous speed a e y auxiliary or starting motor is emplo ed only for starting purposes and is' at all other times idle, 1t is evident that a large starting motor is very undesirable.

The object of my invention is to provide eons whereby a 'much smaller auxiliary mo- 40: mean'be employed for bringing large synchronous dynamo-electric machlnes up to syrichronism than could. heretofore be'employ'ed.

In ,parrymg out my invention,.I provide I means-for starting the dynamo-electric ma- '-chin e'from rest and rovide an auxiliary dynamo-chaotic mac, 'no such as e um- ?nchronous motor. for bringing the main ynamo-electric machine up to speed after ithag niovedfromrest q More cally considered, my inventionconslstiiin the combination of a synchronmlsfflynlino-electric machine mounted 'on a shaft, 8. toothed or notched wheel on 1' being starte Since the the shaft, and means comprisin a piston and rod adapted to beactuate by fluid pressure, such as water, air or oil, for movmg the machine from rest and thus overcome static friction, and a non-synchronous motor also mounted on the shaft for bringin the machine up to synchronism.

invention still further consists in the details of construction and combinations of elements described in the s ecification and set forth in the ap' ended caims.

For a better on erstanding of my inven- .tion, reference is had to-the accompanying drawings in which Figure 1 is a view in elevation of a dynamo-electric machine and the means for starting and bringing the machine up to.

synchronous. spee and Fig. 2 is a view, with parts broken away an m section, of

machine from rest.

Referring nowto the fi res of the drawing, '1 have shown in evation at 10, a dynamo-electric machine which is intended to represent any machine not self starting as machines of the synchronous type, sun 1 as synchronous motors, rotary converters, frequency changers, crother motor generator sets, the rotor of which (not shown) is mounted on the shaft 11 which i? rovided with main bearings 12 and 1 3., eframe of the machine and the shaft bearings are supported on the base 14. Mounted on one end of the shaft is the rotor of an auxiliary non-synchronous motor 15, preferably an the m us for starting the dynamo-electric induction motor. 'The frame andstator of the induction motor" are supported on an extension of the base 14.

As was stated above the static friction of a large synchronous machine is very great and if the motor 15 is reliedupon for bringing the machine 11 ,to'synchronism, a very large motor must, 'e employed. In order that a small motor may be em loyed I provide means no addition to t e motor for overcomin the static friction of the machine or or. starting the, latter from rest. The starting means consists, inthis case, of a fluid actuated means such as a hydraulic or pneumatic jack, the movable piston rod of which is adafted to engage a toothed or notched wheel 7 on the shaft. The jack consists essential? of a cylinder 18, piston 19 and piston r 20 pivoted thereto at 21,

the piston rod having a wrist pin 22 adapted to engage the toothed wheel 17. The cylinder 18 1S sipported on a bracket 18 on the base 14 an is preferably located below the toothed wheel in such a manner that the center of gravity of the piston rod always falls outside of its pivotal center 21. A pair of links ivoted to each other and to the piston rod 20 and cylinder 18, are shown at 23 and 24 respectively, said links serving to automatically lock the piston rod in an inoperative position as will be explained later. The supply pipe shown at 25 15 provided with a main valve 26 and is connected by a nipple 27 to the cylinder 18. At 27' is shown an exhaust valve and at 28 an over-flow pipe with a relief valve 29 adapted to be opened only when the piston 19 has been moved by the fluid pressure to the end of the stroke. The operation of the starting means will now be explained more fully. When it is desired to start the machine 10 the 0 erator by hand lifts the links 23 and 24 so t at the piston rod can be swun about the point 21 into engagement with t e toothed wheel 17. The main valve is then 0 ened and the pressure of the fluid in the cy inder raises the piston and rod, and the latter after engagin a tooth of the wheel 17 turns the shaft an rotor of themain machine. After the shaft has been moved from rest the torque of the motor 15 is sufficient to continue the rota tion of the machine and to accelerate its speed up to synchronisin. Unless the fluid supply 15 shut offthe iston continues its upward movement unti it engages a stop 30and after reachin the end of the stroke the iston rod is t rown away from the whee b. the toothbelow or following the tooth w ich was enga 22. If the fluid supp yis not shut off at the main valve 26 after the piston engages the stop 30, the fluid pressure then becomes suflicient .to open the relief valve 29, and an overflow-occurs throu h the bridging pipe 28. After closing the valve 26, the operator opens the exhaust valve 27 and the p ston falls to the position shown einFig. 1. he wei ht of the piston rod causes the latter to all to the osition shown in dotted linesin Fig. 2 an t e links 23 and 24 also assume the ositiomshown in dotted lines, automatical y locking the piston rod in its ,inoperative position. The particular starting jack and s stem of i in is especially adapted to be operated y hydraulic pressure, but it is evident that the jack can be operated bypneumatic pressure if desired. I do not wish to be confined to the exact details shown as many chan es and modifications can be made without eparting from the spirit and scope of my invention, and I aim in my claims to cover all sucn modifications.

by the wrist pin' What I claim as new and desire to secure by Letters Patent is 1. In combination,a main dynamo-electric machine, means for starting said machine from rest, and an auxiliary dynamo-electric machine for bringing said main dynamoelectric machine up to a predetermined speed. 1 .2. In combination,a synchronous dynamoelectric machine, means actuated by fluid pressure for starting said machine, and an electric motor for bringing said machine up to synchronism.

In combination, a dynamdelectric machine, means for overcoming the'static friction of said machine, and a motor for accelerating the speed of said machine.

4. In combinatlon, a dynamo-electric n1achine comprising a synchronous motor, means actuated by fluid pressure for overcoming the static friction of the machine, and an auxiliary. motor for bringing the dynaimo-electric machine up to synchronous s cc 5. In combination, a synchronous dynamoelectric machine, a shaft therefor, a. toothed or notched wheel on said shaft, means actuated by fluid pressure for engaging said wheel to move the machine from rest, and an electric motor for accelerating the speed of the said machine.

6. In combination, asynchronous dynamoelectric machine, a shaft therefor, a toothed or notched wheel on said shaft,a fluid actua=ed piston and piston rod in proximity to said wheel, whereby said rod can engage said wheel to start the machine from rest, and a non-synchronous motor for bringing the machine up to synchronous speed.

7. In combination, a synchronous dynamoelcctric machine, ashaft, therefor, a toothed or notched wheel on said shaft, fluid actualed means comprising a piston rod adjacent said wheel adapted to engage the latter, and a on being actuated, to start the dynamo electric machine from rest, and a non-syn: chronous motor adapted to accelerate the speed of the dynamo-electric machine.

8. In combination, a synchronous-dynamoelectric machine, a shaft on which said machine is mounted, a toothed or notched wheel on said shaft, a piston below said wheel, a:

pistonr'od adapted to engage a tooth of said wheel and to be moved upwaijdly under fluid ressure to start said-machine, and a motor or bringing the latter up to synchronous speed.

9. In combination, a synchronous dynamoelectric machine a shaft on which said ma chine is mounts a toothed'or notched wheel on said shaft, a piston adjacent said wheeha iston rod pivoted to salddpiston, Islaid movet e w ee cing adapted to engage an and after a predetermined movement under fluid pressure to automatically move out of' engagement with said wheel, and an auxiliary non-synchronmis motor also on said shaft.

10. In combination, name-electric machine, a shaft on which said machine is mounted, a toothed or notched Wheel on said shaft, 3 cylinder and a piston beneath said wheel, a piston rod pivoted to said piston and adapted to engage the wheel and to be moved upward under tiuid pressure to start the machine, and at the end of the stroke of the piston to he moved out of engagement with the wheel, and a non-synchronous motor on. the shaft.

11. In combination, a synchronous dynamo-electric machine, a shaft on which said machine is mounted, means eomprisin" a fluid actuated piston and rod, adaptet to start the machine from rest, means for locking the rod in an inoperative position, and a nonsynchronons motor also mounted on said shaft.

12. In comhination, a motor, means for a synchronous dy overcoming the static friction of said motor, and separate means for accelerating the speed of said motor.

13. In combination, a synchronous dy uamoelectric machine, a shaft on which said machine is mounted, a toothed or notched wheel on said shaft, means comprising a fluid actuated piston and a rod pivoted thereto for starting said machine from rest, said rod being adapted to be moved into engagement with said Wheel and when actuated by fluid pressure to move the machine through a portion of a revolution, and at the end of a stroke to move out of engagement with said wheel, means for locking the rod in an inoperative position, and a non-synchronous motor on the shaft.

' In testimony whereof I afiix my signature, in the presence of two witnesses.

WILLIAM D. POMEROY Witnesses ARTHUR F. Kwis, Fneo J. Kmsnr. 

